1楼哈哈爸
(在这里随手写下你现在的心情)
发表于 2009-5-2 01:18
只看此人
求助
Allen, Benedict and Carl started at the same instant from the same point using the
same route trying to overtake a fourth cyclist Donald traveling at a constant speed ahead of them. Allen and Benedict each took 10 hours and 2 hours respectively to overtake Donald.
Given that Allen, Benedict and Carl each cycled at the constant speed of 4 km/h, 5 km/h and 10 km/h respectively throughout the journey, find the time, in hours, that Carl took to overtake Donald..